The present invention relates to a radio calling receiver for calling and displaying messages or information corresponding to data contained in a radio signal which is transmitted from a base station of a radio calling system.
FIG. 13 is a block circuit diagram showing a circuit configuration of a radio calling receiver in the prior art. In FIG. 13, a reference 21 denotes a receiver portion for receiving a radio signal transmitted from a base station of a radio calling system through an antenna 21a and then demodulating the radio signal into a digital signal; 22, a decoder for executing a bit synchronization and error correction process of the received signal being converted into the digital signal and then collating an address contained in the received signal with an own address stored in a memory 23; 23, a memory having a memory device, e.g., an EEPROM (Electrically Erasable Programmable Read Only Memory) into which data can be electrically erased and written, and for storing the own address of the radio calling receiver; and 24, a CPU (Central Processing Unit) for controlling peripheral circuits based on the received signal transmitted from the decoder 22. A reference 25 denotes a display driver for driving a display 26 based on a display signal supplied from the CPU 24; 26, a display for displaying the messages in response to the display signal by using a liquid crystal display device when it is driven by the display driver 25; and 27, a switch for generating commands and various data corresponding to an operation instructed by a user. A signal output from the switch 27 is input into the CPU 24 via the decoder 22. A reference 28 denotes a speaker driver for generating a ringer tone by sounding a ringing speaker 29, and a reference 30 denotes a vibrator driver for controlling vibrations of a vibrator 31.
Next, an operation of the above radio calling receiver will be explained hereunder. The receiver portion 21 first receives the radio signal transmitted from the base station of the radio calling system (referred to simply as the "base station" hereinafter) via the antenna 21a at a predetermined timing controlled by the CPU 24, then converts this received radio signal into the digital signal via amplification, frequency-conversion, detection, and demodulation processes, and then sends out the digital signal to the decoder 22. Then, the decoder 22 executes the bit synchronization and error correction process of the digital signal received from the receiver portion 21, then collates the address contained in the received signal with the own address read out from the memory 23 via the CPU 24, and then decides whether or not the received signal is directed to own radio calling receiver.
If the received signal is directed to the own radio calling receiver and message data are contained in the received signal, the decoder 22 fetches the message data from the received signal, then sends out the message data to the CPU 24, and then outputs a drive signal to the speaker driver 28 or the vibrator driver 30. The speaker driver 28 generates the ringer tone by driving the ringing speaker 29 in answer to inputting of the drive signal. Otherwise, if the radio calling receiver is set into a calling operation for the vibrator 31 in advance, it can output the drive signal only to the vibrator driver 30 to cause the vibrator 31 to vibrate. In parallel to this calling operation, the CPU 24 converts the message data into a display signal, which is composed of an assembly of predetermined bit number of bit codes, and then sends out the display signal to the display driver 25. Then, the display driver 25 displays predetermined messages corresponding to the message data on the display 26 by driving the display 26 based on the display signal sent out from the CPU 24.
In this manner, the conventional radio calling receiver can receive the radio signal transmitted from the base station, then execute the ringing operation by using the ringer tone and then display the messages contained in the radio signal by use of characters.
However, in the above-mentioned conventional radio calling receiver, in the event that normal individual calling messages and information broadcasting messages which can broadcast information such as news, weather forecast, for example, are to be received by using separate receiving frames, a receiving operation for individual calling and a receiving operation for information broadcasting must be repeated at constant cycles respectively. For this reason, the radio calling receiver in the prior art has had such a problem that, the number of the receiving operation per a constant time is increased rather than the case where only the receiving frame for individual calling is to be received, so that the radio calling receiver must repeat receiving operations which are disadvantageous for battery lifetime.